<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
<style>
    *{
        margin: 0;
        padding: 0;
    }
    ul{
        display: flex;
        border-bottom: 2px solid #e01222;
        padding: 0 10px;
    }
    li{
        width: 100px;
        height: 50px;
        line-height: 50px;
        list-style: none;
        text-align: center;
    }
    li a{
        display: block;
        text-decoration: none;
        font-weight: bold;
        color: #333333;
    }
    li a.active{
        background-color: #e01222;
        color: aliceblue;
    }

</style>
</head>
<body>
    <div id="app">
       <ul>
        <li v-for="(item,index) in list" :key="item.id">
            <a @click="activeIndex = index" :class="{active:index === activeIndex}" href="#">{{item.name}}</a>
        </li>
       </ul>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.16/dist/vue.js"></script>
    <script>
        const app = new Vue({
            el:'#app',
            data:{
                //用户记录当前高亮的索引号
                activeIndex:0,
               list:[
                {id:1,name:'京东秒杀'},
                {id:2,name:'每日特价'},
                {id:3,name:'品类秒杀'}
               ]
            },
        })
    </script>
</body>
</html>